1. Field of the Invention
The present invention relates to a multi-cylinder rotary compressor capable of switching compression capacities and a refrigeration cycle apparatus that configures a refrigeration cycle by including the multi-cylinder rotary compressor.
2. Description of the Related Art
In a refrigeration cycle apparatus, multi-cylinder rotary compressors including a plurality of cylinder chambers (mainly two) in a compression mechanism unit are frequently used. Such a kind of compressor is advantageous if it is possible to carry out switching between the so-called full-capacity operation and capacity reduced operation in which compression operation is performed in a plurality of cylinder chambers simultaneously or compression operation is reduced by stopping the compression operation in one cylinder chamber respectively.
Jpn. Pat. Appln. KOKAI Publication No. 2006-300048 discloses a compressor including a first cylinder and a second cylinder, wherein suction pressure is guided into the cylinder chamber of the first cylinder and suction pressure or discharge pressure is guided into the cylinder chamber of the second cylinder. The first cylinder includes a vane chamber containing a rear-side end of a vane and a spring member and the second cylinder includes a vane chamber that contains the rear-side end of the vane and is sealed.
Then, suction pressure or discharge pressure is guided into the second vane chamber to energize pressing of the vane in accordance with a differential pressure between the suction pressure and the discharge pressure guided into the second cylinder chamber. Thus, an enclosed compressor capable of switching between the full-capacity operation that performs compression operation by using both cylinder chambers and the capacity reduced operation in which the compression operation is not performed in the second cylinder chamber is disclosed.
The second vane chamber described above has a sealed structure and thus, a sliding contact surface between a vane groove communicatively connecting to the vane chamber of the second cylinder and both side surfaces of the vane reciprocating in the vane groove needs oiling. Thus, according to the above technology, an oil groove to introduce lubricating oil into the vane groove is provided and also an oil communication hole is included in a sub-bearing.